Abstract:The annual new steel slag discharge in China is more than 100 million tons, and the utilization rate is only 10%~20%. There are abundant resources such as “slag, iron and heat ” in the liquid steel slag of converter, which causes great waste by simple storage or landfill. At present, the mainstream technologies of steel slag granulation mainly include hot stuffy method, air quenching granulation method, drum method, etc., which are all based on the development of steel slag granulation and free calcium oxide (f-CaO) digestion, which is convenient for subsequent crushing, screening and magnetic separation to obtain slag steel, magnetic separation powder and tailings. Although these methods have solved the problems of large investment, large land occupation and heavy pollution in other methods to a certain extent, there are still some problems such as incomplete utilization of steel slag resources, risk of volume stability, high grinding cost and high iron content. The author proposes to use the combination of modified reconstruction and gas-water two-phase mixed fluid quenching granulation technology to treat steel slag. This method adds acid flux and reducing agent to liquid steel slag, and uses the high speed of gas and the high thermal conductivity of water to quickly cool the liquid steel slag into solid particles, which reduces the fibrosis of steel slag and takes into account the granulation of reconstructed slag and the efficiency of waste heat recovery. The tailings after iron extraction can be used in the fields of building materials preparation, soil modification, glass-ceramic and ceramic materials after particle size classification. However, this method is still in the research stage and not mature enough. In the later stage, it is necessary to carry out in-depth research on the preparation of high-performance steel slag granulation materials, environmental protection utilization and resource utilization, and the development of steel slag deep processing.
